How Many Bridges Are There?

One of the most frequently asked questions is “How many bridges are there on the Road to Hāna?”. There are many different answers to this ambiguous question and to better explain, you’ll need to know a few things first, like where do you start and end your count and do you include culverts?

The first deciding factor is where you start and end your count. While you can start your ”Road to Hāna” bridge count from your hotel, Kahului, Pai’a or the beginning of Route 360, the official Hāna Highway Historic District begins at approximately mile marker (MM) 3.2 on Route 360 just after Twin Falls and ends beyond Hāna town at MM 40.6 on Route 31 just past Kīpahulu and Haleakalā National Park’s ‘Ohe’o Gulch. Being the most scenic portion of the Hāna Belt Road System, this Historic District of the “Road to Hāna” is relatively unaltered, retains its historic character and has the highest concentration of stylistically consistent historic bridges, culverts and weirs in the State of Hawai’i.

1929 Holua Bridge. Reinforced Concrete T-beam with Open Parapet and balusters. MM 5.1 the 1st historic bridge along the road to Hāna

The first historical bridge is the 1929 concrete T-beam Holua Bridge at MM 5 and the last is the 1911 open spandrel concrete arch Koukou’ai (Kaukau’ai) Bridge at MM 40.6 (past Hāna), an engineering marvel of it’s day. The bridges along this Hāna Highway Historic District are the ones we count.

Another deciding factor when determining the number of bridges is to determine if the culverts count. To answer this, you must know the difference between a bridge and a culvert. Bridges are used to provide passage of people and vehicles over gulches and bodies of water. Culverts are used to provide a passage of water across obstacles like a roadway. Keep in mind, bridges have no floors, whereas culverts have a floor and are circular, rectangular, elliptical, or even square in size. However, if the length of the culvert’s span is greater than 20 feet, it is officially categorized as a bridge like the 1947 33ft 2 span concrete girder and box culvert Kawaipapa Bridge at MM 33.4 in Hāna town.

So, do culverts count? There are 15 spans along the historical “Road to Hāna” that are classified as culverts. These culverts are located within the historic section and share the same construction material, design style and timeframe of the bridges in the historic district yet they are not officially bridges.

Enough confusion? Here is the official count: 59 bridges and 15 culverts giving us a total of 74 man-made historical “spans” along the “Road to Hana”.

SIDE NOTE: The U.S Department of the Interior, National Park Service confirms this count in its Hāna Belt Road National Register of Historic Places and in its Historic American Engineering Field Record Bridge Inventory; however, there is a conflict in the latter document stating that there are “seventy-seven bridges (including some called ‘culverts’)”. So where are these 3 missing historical bridges?

There are 3 more historic bridges just past the end of the official historic district. The 1947 Lelkea (Kaapahu) Bridge at MM 39, the 1937 Alalele Bridge at MM 38.7 and the 1937 Kalepa Bridge at MM 38.5. If we add these to our count, we have 77 man-made historical “spans”, 62 bridges and 15 culverts.